\(\begin{array}{*{20}{c}} {Zn}& < &{Cr}& < &{Fe}& < &{Co}& < &{Cu} \\ \downarrow &{}& \downarrow &{}& \downarrow &{}& \downarrow &{}& \downarrow \\ {7.1}&{}&{7.19}&{}&{7.8}&{}&{8.7}&{}&{8.9} \end{array}\)
[ આપેલ : પરમાણુ ક્માંક : $\mathrm{C}: 6, \mathrm{Na}: 11, \mathrm{O}: 8, \mathrm{Fe}: 26, \mathrm{Cr}: 24]$